Sometimes you need to just run from your car and grab something real quick, so you leave the engine running while you pop into the shop for a Cornetto. Would you do that, though, if your car was a Bugatti Veyron, and you were in the middle of London?
This video from the guys at Shmee150 shows a cream (or is it eggshell? Discuss below in the comments) Bugatti Veyron with Dubai plates pulling up to the curb on a busy London street. The driver hops out and runs away for a second, all 16 cylinders of the Bug's engine still happily thrumming away. He's either incredibly brave or incredibly careless.
I suppose the traffic might be a hindrance, but given an open road there's no way the cops could catch you at more than 250 miles per hour.